Surface wave (also known as the Zenneck wave) propagation along a conductor surface is a phenomenon first observed and theoretically investigated many years ago. It has been previously demonstrated that a transmission wire has practical implication as a surface waveguide. If a conductor has a threaded surface over which an electromagnetic (EM) wave can glide or a dielectric coating though which the wave can travel, then surface EM waves can efficiently propagate along the conductor. More recently, a device has been shown which can excite transverse magnetic waves along a single conductor wire. The device includes a conical shape slotted launcher which could be mounted on an existing stranded aluminum overhead power line as shown in FIG. 1. For a transmitter and a receiver placed apart a certain distance along the conductor, it was demonstrated that a bandpass transmission response (S21) centered at approximately 2 GHz could be achieved.
However the surface wave devices proposed thus far are not suitable for use with unshielded insulated power line cables used in overhead power lines, industrial settings, inside conduits, shipboard and aircrafts because of their large size, weight, and non-conformal construction.
Thus, improvements in surface wave devices are still needed. The ability for such devices to detect cable faults would be particularly desirable.